UVICS and Son Of UVICS project files updated at Geofex

[R.G.]

One hardy builder of UVICS (Univibe In a Crybaby Shell) had some problems, and I wound up looking over the PCB. He did a neat build job, but (like I always do) there were a few soldering problems. However, I did find some bugs in the documentation - my bad there.

Accordingly, I've updated the docos on UVICS  and Son of UVICS, which offers lots of mod options.

Every time I type, even correcting errors, there is the chance that I introduce errors, so don't be afraid to point them out to me.

Big deal: the replaced docos left off noting a jumper.

Smaller deal: using all 2N5088s for the transistors caused oscillation in the first three-transistor stage. Apparently these were either very high gain or high phase shift or both devices. The stock C4=330pF to ground would not cure the oscillation. However, my compensation modification of making C4 be 30pF and moving it to connect Q2 collector and Q2 emitter promptly stopped this.

Moderate deal: the builder used a 9V-to-17v upverter from an LT1054 and it was quite noisy. This is one of the possible issues with a charge pump making higher voltages for you. It is often a layout issue. The builder didn't use the layout for the upverter in the article, which I designed to be as noise free as I could, but Mother Nature always has surprises for me, so noise in an upverter will always be something you have to watch for.

Comments welcome.

Hey, who's built these?